91 lines
3.1 KiB
Markdown
91 lines
3.1 KiB
Markdown
---
|
|
title: Retrieving metadata
|
|
---
|
|
|
|
## During playback ##
|
|
|
|
The metadata of the media can be retrieved during playback in multiple ways. The
|
|
most straightforward is to listen for the
|
|
`Player.Listener#onMediaMetadataChanged` event; this will provide a
|
|
[`MediaMetadata`][] object for use, which has fields such as `title` and
|
|
`albumArtist`. Alternatively, calling `Player#getMediaMetadata` returns the same
|
|
object.
|
|
|
|
~~~
|
|
public void onMediaMetadataChanged(MediaMetadata mediaMetadata) {
|
|
if (mediaMetadata.title != null) {
|
|
handleTitle(mediaMetadata.title);
|
|
}
|
|
}
|
|
|
|
~~~
|
|
{: .language-java}
|
|
|
|
If an application needs access to specific [`Metadata.Entry`][] objects, then it
|
|
should add a `MetadataOutput` (for dynamic metadata delivered during
|
|
playback) to the player. Alternatively, if there is a need to look at static
|
|
metadata, this can be accessed through the `TrackSelections#getFormat`. Both of
|
|
these options are used to populate the `Player#getMediaMetadata`.
|
|
|
|
## Without playback ##
|
|
|
|
If playback is not needed, it is more efficient to use the
|
|
[`MetadataRetriever`][] to extract the metadata because it avoids having to
|
|
create and prepare a player.
|
|
|
|
~~~
|
|
ListenableFuture<TrackGroupArray> trackGroupsFuture =
|
|
MetadataRetriever.retrieveMetadata(context, mediaItem);
|
|
Futures.addCallback(
|
|
trackGroupsFuture,
|
|
new FutureCallback<TrackGroupArray>() {
|
|
@Override
|
|
public void onSuccess(TrackGroupArray trackGroups) {
|
|
handleMetadata(trackGroups);
|
|
}
|
|
|
|
@Override
|
|
public void onFailure(Throwable t) {
|
|
handleFailure(t);
|
|
}
|
|
},
|
|
executor);
|
|
~~~
|
|
{: .language-java}
|
|
|
|
## Motion photos ##
|
|
|
|
It is also possible to extract the metadata of a motion photo, containing the
|
|
image and video offset and length for example. The supported formats are:
|
|
|
|
* JPEG motion photos recorded by Google Pixel and Samsung camera apps. This
|
|
format is playable by ExoPlayer and the associated metadata can therefore be
|
|
retrieved with a player or using the `MetadataRetriever`.
|
|
* HEIC motion photos recorded by Google Pixel and Samsung camera apps. This
|
|
format is currently not playable by ExoPlayer and the associated metadata
|
|
should therefore be retrieved using the `MetadataRetriever`.
|
|
|
|
For motion photos, the `TrackGroupArray` obtained with the `MetadataRetriever`
|
|
contains a `TrackGroup` with a single `Format` enclosing a
|
|
[`MotionPhotoMetadata`][] metadata entry.
|
|
|
|
~~~
|
|
for (int i = 0; i < trackGroups.length; i++) {
|
|
TrackGroup trackGroup = trackGroups.get(i);
|
|
Metadata metadata = trackGroup.getFormat(0).metadata;
|
|
if (metadata != null && metadata.length() == 1) {
|
|
Metadata.Entry metadataEntry = metadata.get(0);
|
|
if (metadataEntry instanceof MotionPhotoMetadata) {
|
|
MotionPhotoMetadata motionPhotoMetadata = (MotionPhotoMetadata) metadataEntry;
|
|
handleMotionPhotoMetadata(motionPhotoMetadata);
|
|
}
|
|
}
|
|
}
|
|
~~~
|
|
{: .language-java}
|
|
|
|
[`MediaMetadata`]: {{ site.exo_sdk }}/MediaMetadata.html
|
|
[`Metadata.Entry`]: {{ site.exo_sdk}}/metadata/Metadata.Entry.html
|
|
[`MetadataRetriever`]: {{ site.exo_sdk }}/MetadataRetriever.html
|
|
[`MotionPhotoMetadata`]: {{ site.exo_sdk }}/metadata/mp4/MotionPhotoMetadata.html
|